AUTOMATIC SHIELD FOR SMOKE OUTLET OF FLUE

PROBLEM TO BE SOLVED: To facilitate mantling/dismantling work of a temporary roof at the time of inspecting/repairing a stack by providing a shielding plate covering the smoke outlet on top of a chimney such that it can move between a shielding position and a side containing position through a shielding plate moving mechanism. SOLUTION: A stretching table 15 is disposed closely to the top of a stack 11 and the automatic shielding unit 16 for a smoke outlet 14 is disposed on the table 15 and a nozzle structure 13. The unit 16 comprises a shielding plate winding/containing box 17 with a driver, and a pair of guide rails 18 for the shielding plate. A shielding plate 20 is supported, at the opposite ends thereof, movably on the guide rails 18 through a roller chain, or the like, so that it can be fed out onto the smoke outlet 14 or pulled in therefrom through the driver of the containing box 17. When smoke discharge of the stack 11 is stopped, the automatic shielding unit 16 controls the drive system of the containing box 17 through a remote operating board 26 to feed out the shielding plate 20 from the box 17 onto the smoke outlet 14 thus shielding the smoke outlet 14 in a short time.